If numbers out of Michigan are an indicator, a massive outbreak of infections from the Cyclospora parasite may be slightly slowing.
On July 30 the state reported 10,386 patients, up from 10,077 on July 29. That’s the smallest overnight increase for more than a week in Michigan. Of the Michigan patients for whom complete information is known, 193 report being hospitalized.
“Typically, outbreaks of this type do have their natural history,” Craig Hedberg, PhD, professor of environmental health sciences at the University of Minnesota’s School of Public Health, told CIDRAP News. “We may well be on a downslope.”
The Centers for Disease Control and Prevention is expected to update its patient counts next week. As of this week the agency was reporting that since May 1 there have been 6,707 domestically acquired, lab-confirmed cases of cyclosporiasis, and an additional 11,500 are awaiting confirmation or need more investigation. Those numbers are for the largest outbreak which spans 45 states. A source of the parasite for this outbreak has not yet been determined.
For a smaller outbreak including nine states — Illinois, Indiana, Kansas, Kentucky, Michigan, Ohio, Oklahoma, Pennsylvania, and West Virginia — the CDC has not yet updated its patient count of 1,947. Interviews with people sickened with cyclosporiasis in this outbreak indicate that many in those states ate at Taco Bell restaurants and ate lettuce distributed by Taylor Farms de Mexico. That lettuce has since been recalled, but the recall was initiated after the lettuce was consumed or past its expiration date.
The larger outbreak that involves 10,386 patients in Michigan has 2,926 patients in Northern Ohio. Several other states have numbers in the hundreds and count are still growing, but not at as fast a pace that they have been.
About Cyclospora
Anyone who has developed symptoms of Cyclospora infection, and has reason to believe they have been exposed to the parasite, should seek medical attention. Specific tests are required and antibiotics are used to fight the parasite.
Cyclospora infection can cause severe abdominal pain, severe watery diarrhea, nausea, vomiting, body aches, and fatigue. Symptoms can develop between two and 14 days after exposure. Though symptoms can be severe enough to send people to the hospital, it's rare for people to die from Cyclospora infections.
Symptoms can last for a month or more and can reoccur for several more months if not treated.
Cyclospora is a type of protozoa, which is a single-celled organism. It is transmitted when people somehow ingest contaminated feces, typically through contaminated food or water. It can be spread only through human waste, unlike E. coli and salmonella, which can also be spread from animal fecal matter.
Previous U.S. outbreaks of cyclosporiasis have been linked to various types of fresh produce, including lettuce, basil, cilantro, mesclun lettuce, raspberries, and snow peas.
Food safety experts say there's no evidence that washing the produce will remove the parasite because it becomes embedded in the flesh of the produce.
